Bench tests for CPubKey<->EllSwift

src/Makefile.bench.include

@@ -28,6 +28,7 @@ bench_bench_bitcoin_SOURCES = \
   bench/data.cpp \
   bench/data.h \
   bench/duplicate_inputs.cpp \
+  bench/ellswift.cpp \
   bench/examples.cpp \
   bench/gcs_filter.cpp \
   bench/hashpadding.cpp \

src/bench/ellswift.cpp

@@ -0,0 +1,28 @@
+// Copyright (c) 2016-2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <bench/bench.h>
+
+#include <key.h>
+#include <pubkey.h>
+#include <random.h>
+
+#include <array>
+
+static void EllSwiftEncode(benchmark::Bench& bench)
+{
+    ECC_Start();
+    std::array<uint8_t, 32> rnd32;
+    GetRandBytes(rnd32);
+
+    CKey key;
+    key.MakeNewKey(false);
+    auto pubkey = key.GetPubKey();
+
+    bench.batch(1).unit("pubkey").run([&] {
+        pubkey.EllSwiftEncode(rnd32);
+    });
+}
+
+BENCHMARK(EllSwiftEncode);